Administration: Individual. The DAB-4 is a revision of one of the most popular individual achievement tests available. Its 8 subtests identify studentsâ strengths and weaknesses across important areas of school achievement. A supplemental manual shows how to probe student responses to obtain information about studentsâ thinking processes and problem-solving strategies.
In 1992, the first evidence of a planetary system other than our own was discovered, orbiting the pulsar PSR B1257+12. Three years later, 51 Pegasi b, the first extrasolar planet around a Sunlike star, was discovered.
Later, in the early 21st century, many objects similar to Pluto were discovered in the outer solar system, notably the scattered disc object Eris, which is 27% more massive than Pluto. On August 24, 2006, the IAU defined the term planet for the first time. This definition excluded Pluto as a planet, and added it as a member of the new category dwarf planet along with Eris and Ceres. After the reclassification, Pluto was added to the list of minor planets and given the number 134340.